METHOD, APPARATUS, AND PROGRAM FOR URBAN AREA EXTRACTION, AND RECORDING MEDIUM FOR THE PROGRAM

摘要

PROBLEM TO BE SOLVED: To stably extract an urban area by paying attention to texture features in the urban area when the urban area is automatically extracted from a satellite photographic image, an aerial photographic image, etc. SOLUTION: A two-dimensional edge vector is obtained as to each pixel of an image of an object of urban area extraction and in a block including the pixel as the center, the sum of outer products of a combination of two of all vectors is calculated to decide whether a representative point in the block is in an urban area. Further, lateral and longitudinal edge differences of each pixel in the block including each pixel as the center are calculated to find an edge tangent parameter and Hough transformation is performed for it to decide whether a representative point in the block is in the urban area according to a polling result. Furthermore, a water area and a forest area are found by using images of the red range and near infrared ranges of visible light and used to decide on the urban area. COPYRIGHT: (C)2004,JPO